Proton pump inhibitors represented by omeprazole, which suppress secretion of gastric acid for the treatment of peptic ulcer, reflux esophagitis and the like, have been widely used in clinical situations. However, the existing proton pump inhibitors are associated with problems in terms of effect and side effects. To be specific, since the existing proton pump inhibitors are unstable under acidic conditions, they are often formulated as enteric preparations, in which case several hours are required before expression of the effect. In addition, since the existing proton pump inhibitors show inconsistent treatment effects due to metabolic enzyme polymorphism and drug interaction with pharmaceutical agents such as diazepam and the like, an improvement has been desired.
As a compound having a proton pump inhibitory action, a thiazole derivative is described in patent reference 1.
As a compound having a thromboxane A2 (TXA2) antagonistic action and TXA2 synthase inhibitory action, patent reference 2 describes a compound represented by the formula
wherein r1 is carboxy, protected carboxy, carboxy(lower)alkyl, protected carboxy(lower)alkyl, carboxy(lower)alkenyl or protected carboxy(lower)alkenyl, r2 is hydrogen; lower alkyl; aminoimino or heterocyclic (lower)alkyl optionally having protected aminoimino; heterocyclic (lower)alkenyl; or heterocyclic carbonyl, r3 is hydrogen or lower alkyl, r4 is acyl, r5 is hydrogen, A0 is lower alkylene, Z0 is S or NH, and when r1 is carboxy or protected carboxy, then Z0 is NH.
As a therapeutic drug for neoplastic diseases and autoimmune diseases, patent reference 3 describes a compound represented by the formula
wherein r6 is aryl, aralkyl or heteroaryl, r7 is aryl or heteroaryl, and r8 is aryl, heteroaryl or optionally substituted aminomethyl.
In addition, patent reference 4 describes a pyridyl or imidazolyl derivative having a protein•isoprenyl•transferase inhibitory action.    patent reference 1: EP-A-0259085    patent reference 2: JP-A-8-119936    patent reference 3: WO2004/103968    patent reference 4: US2002/0193596